High Purity Grade Hydrogen is an important compound used in oil refineries due to its capacity for withdrawing sulfur impurities from fuels. This feedstock is commonly produced in Hydrogen Generation Units through a Steam Methane Reforming process. Due to the high-grade requirements in Hydrotreament processes, a hydrogen purification step is mandatory, often conducted in batteries of adsorption columns, known as Pressure Swing Adsorption (PSA). The main objective of this paper is to present the simulation of a Hydrogen Generation Unit, focusing on the PSA process modeling approach. ASPEN PLUS™ was utilized in conjunction with MATLAB ® to model the whole process. The link between both simulators was established through VBA (Visual Basic for Applications) macros developed in Excel. This two-way connection did not affect the results obtained by the simulation of the whole process unit, as it was carried out successfully and was able to represent the global mass and energy balances satisfactory, obtaining hydrogen with 99.8% purity.

Chemical engineering involves a skill set that is transferrable to a broad range of other areas. A case in point is the work that is being done by chemical engineers to better understand and fight the COVID‐19 epidemic. In this study, we consider a problem that has eluded the COVID‐19 research community, which is nevertheless very tractable with a chemical engineering mindset: the true or intrinsic mortality rate of COVID‐19, i.e., the fraction or percentage of COVID‐19 infected people that die of the disease. We solve this problem in two locations (Spain and the state of New York) for the epidemic's first wave with a combination of daily death data, a fit of a computer simulation of an epidemiological model with adjustable parameters, and independent results of immunological blood testing on a random sample of the population. Parallels are drawn with the problem of determining the turnover frequency of a catalyst based on a similar combination of data and approaches. It is concluded from the study that the intrinsic mortality rate of COVID‐19 was 1.45 ± 0.45 % during the first wave, a number that reflects OECD countries. By incorporating data on the age dependence of the mortality rate, a relationship f mort = (3.0 ± 0.7)×10 −5 exp(0.1 a ), where a is the age in years, is tentatively put forward for the mortality rate as a fraction. This article is protected by copyright. All rights reserved.

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<p>O Sistema de treinamento de Operadores (OTS) permite um treinamento sem riscos de acidentes e sem perdas de insumos e de tempo. A modelagem e simulação da operação associada aos dados de entrada no modelo, que são as variáveis manipuladas pelos operadores, geram resultados virtuais com comportamento similar aos que seriam gerados se o treinamento estivesse sendo feito nos equipamentos. O objetivo deste trabalho foi desenvolver um modelo matemático simples para o processo de purificação de hidrogênio em uma coluna de adsorção. Tal modelo poderá ser empregado na proposta de OTSs sem a necessidade de lidar com modelos com significativa complexidade matemática. O modelo proposto foi validado empregando-se dois casos reportados na literatura. Assim, foi possível concluir que esse descreve o processo de adsorção satisfatoriamente e poderá ser utilizado posteriormente no desenvolvimento de um OTS para todo o processo de purificação de hidrogênio.</p><p>ABSTRACT </p><p>Operator Training System allows training without risk of accident and no loss of material and time. Modeling and simulation of operation associated with inputs, which are manipulated variables by operators, generate virtual results with similar behavior to that would be generated if the training was being done on the equipment. The aim of this work was to develop a simple mathematical model for the adsorption process for hydrogen purification. This model can be used in the proposal for OTSs without having to handle models with significant mathematical complexity. The proposed model has been validated employing two reported cases in the literature. Thus, it was concluded that this model describes the adsorption process satisfactorily and it can be used for a future development of an OTS for the entire hydrogen purification process.</p>